You Could Own Your Very Own Land Speed Record Car

One of our favourite pastimes at Car Throttle on slow news days – and there are many of those at this time of year – is to peruse the upcoming lots of some fancy car auction house. Normally we’ll pick out a collector-friendly modern JDM classic, or maybe a rare-groove supercar, but this time, we’ve found something a little bit different: the Spirit of America Sonic I.

Between 15 November 1965 and 23 October 1970, it was the fastest thing to have ever travelled across land in human history. Built by certified speed enthusiast Craig Breedlove, it arrived at a time when the outright land speed record was hotly contested, changing hands some eight times between August 1963 and Breedlove’s November ’65 run.

Unsurprisingly given it was designed to go as fast as 1960s engineering would allow, Sonic I was pretty much a fighter jet with its wings swapped out for wheels. The 34-foot long fuselage housed a General Electric J79 turbojet engine, better known for powering the F-4 Phantom interceptor jet.

With its afterburner on (yes, it had an afterburner. How cool is that?), this powerplant churned out around 15,000lbs of thrust. Now, because they measure different things, you can’t really convert thrust to horsepower, but let’s just assume it made a lot.

Enough to make Sonic I the first landgoing vehicle to break the 600mph barrier, which is just what Breedlove did on the Bonneville Salt Flats on that November day, definitively ending the year-long back-and-forth he’d been having with fellow velocity enjoyers Art Arfons and Tom Green. 600.601mph over a mile was the actual record, and it would be another five years before it was broken by Gary Gabelich’s Blue Flame.

In fact, since Breedlove’s record-setting run in 1965, the record’s only been broken four more times – Andy Green’s 763mph run in ThrustSSC in 1997 remains the benchmark, and the only one to push past the sound barrier.

For good measure, after his run, Breedlove’s wife Lee jumped in Sonic I and took it to 308.506mph, becoming the fastest woman in history in the process – a record that’s since only been broken twice.

After its retirement, Sonic I has resided largely in the Indianapolis Motor Speedway Museum, but it’s now up for grabs at RM Sotheby’s’ Miami sale between 27 and 28 February 2025. Estimated at £395-800,000, it could go for significantly less than any number of modern hypercars that can just about crack a measly 200mph.

 Then again, it doesn’t currently have an engine in it, and we’re not sure about the going rate of second-hand F-4 Phantoms and large expanses of flat, empty desert should you want to make your own attempt on 600mph.